Cu2O nanowires were successfully synthesized by an electrochemical method using alumina membrane as template. The composition and morphology of nanowires were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photo-potential and electrochemical impedance spectroscopy experiments of Cu2O/AAO were also performed. The results showed that the diameter of the Cu2O nanowires was about 120 nm and their length was 2 μm. The photo-potential was about 25 mV and the electrochemical impedance of Cu2O/AAO was much smaller under the light of 365 nm.